The fashion is now for landscape architects to design modernist spaces that require no planting, said Alan Titchmarsh and Diarmuid Gavin.

They were backed up by Luciano Guibbilei, the acclaimed designer and a favourite to win a medal at this year’sChelsea Flower Show, who said those yearning for a no maintenance garden should “go and play golf” instead.

Giubbilei, who has designed the Laurent-Perrier Garden, declared: “This idea of low-maintenance gardens – I’ve no idea who told this to people. It does not exist. The people that want no-maintenance gardens, they should go and play golf. That is what they should be doing.

Speaking at Chelsea, Titchmarsh said: “At the top end of garden design now, that’s what people are asking for: they want a sitting room that’s outside, where nothing grows, where it’s all squares, all clean lines, no curves, nothing natural-looking, no wildlife.

“For me, that’s not a garden. That’s what a lot of top end designers are having to do now and they’re getting frustrated.”

In decades gone by, homeowners who comissioned garden designers had a passion for gardening. “They used to buy plants and seeds, they used to grow things. We’re lacking that kind of patron now who’s a real grower,” Titchmarsh said.

Gavin suggested some people were put off by the "untidy" effect created by plants and flowers that encourage wildlife. “A low-maintenance garden tends to be soulless, and for passion to really come out you have to get in there, you have to understand the soil, you have to work at it.

“And you have to have a range of plants these days that are not only suitable for you but also to encourage wildlife. That can be a bit untidy.”

Cleve West, who won the top award at Chelsea in 2011 and 2012, said he turns down commissions from potential customers who spend their money on flashy house extensions and want the back garden to be little more than an add-on to the kitchen.

“I tend to shy away from jobs where they just want to extend the house and make the footprint so large that there’s no room for planting. Those kind of jobs don’t really interest me. It’s a case of waiting for clients who are a little bit more interested in plants,” West said.

“I have turned people down who, when they show me the plans for the extension, have a fair-sized garden but want to extend so much that the footprint of the whole thing just looks ridiculous.”